The present invention relates to bioassay devices, and more particularly to a pipette-loaded bioassay assembly operable to detect and identify molecular and cellular activity in a sample solution.
The applicant, in PCT publication number WO 99/39190, has previously discussed the need of a system to determine the ability of molecules of interest to interact with other molecules. Likewise, the ability to detect the physical and functional properties of biological molecules and cells on a small scale is highly desirable. Such molecular interactions, as well as the detection of functional and physical properties of these biological molecules and cells in an aqueous environment are referred to here as xe2x80x9cmolecular eventsxe2x80x9d and xe2x80x9ccellular events,xe2x80x9d respectively.
The occurrence of molecular or cellular events in a test sample can be detected by illuminating the test sample with an electromagnetic test signal and recovering the resulting modulated signal, the modulation being indicative of the molecular or cellular event occurring within the sample. The applicant has presented several bioassay structures capable of this process in PCT publication nos. WO 01/20239 and WO 01/27610 in addition to the aforementioned publication.
The applicant has additionally described various sample handling structures used to supply sample to the bioassay structure. Exemplary structures include microfluidic devices, flow tubes, flow cells, and sample cavities.
In addition to these sample handling structures, pipette tips are commonly used to transport sample. For example, automated sample processors are often equipped with pipette tips for transporting sample to/from bioassay structures. These systems are advantageous in that they can aspirate, transport, and dispense small, precise amounts of sample to one or more bioassay devices at high speeds for extended periods of time without human intervention.
What is therefore needed is a pipette-compatible bioassay assembly that is operable to detect molecular and cellular events using applicant""s technique of illuminating the supplied sample with an electromagnetic signal.
The present invention provides a pipette-loaded bioassay assembly operable to identify molecular or cellular events in a test sample. In one embodiment, the pipette-loaded bioassay assembly includes a measurement probe and a pipette tip. The measurement probe includes a probe head configured to launch an incident test signal and a connecting end configured to receive the incident test signal from a signal source. The pipette tip includes a sample interrogation region which is electromagnetically coupled to the probe head, the sample interrogation region configured to retain a plug of sample solution and constructed from a material which is substantially transparent to the incident test signal. The incident test signal electromagnetically couples through the sample interrogation region and to the molecular or cellular events occurring within the sample solution. The interaction of the incident test signal with the molecular or cellular events produces a modulated test signal which can be recovered and used to identify the molecular or cellular events occurring in a subsequently tested sample.
Other advantages and aspects of the invention will be apparent when considered in view of the following drawings and description.